#! /usr/bin/python 
# Author: Tanghong Qiu

# Multiples of 3 and 5
#
# If we list all the natural numbers below 10 that are multiples of 3 or 5, 
#  we get 3, 5, 6 and 9. The sum of these multiples is 23.
# Find the sum of all the multiples of 3 or 5 below 1000.
#
# result: 233168  

def main():
    multiples = set(find_mul(3, 1000)) | set(find_mul(5, 1000))
    print sum(multiples)

def find_mul(step, upper):
    return range(step, upper, step)

if __name__ == "__main__":
	main()
